检索结果-内蒙古大学图书馆

Efficient reduction of peak-to-average power ratio in multiple-input multiple-output orthogonal frequency-division multiplexing system by shuffling cluster sequences

引用

ETRI JOURNAL 2024年第6期46卷 998-1006页

作者： Mi, Si Sar Mata, Tanairat Boonsrimuang, Pornpawit Boonsrimuang, Pisit King Mongkuts Inst Technol Ladkrabang Fac Engn Dept Telecommun Engn Bangkok Thailand Rajamangala Univ Technol Krungthep Fac Engn Dept Elect & Telecommun Engn Bangkok Thailand Suan Sunandha Rajabhat Univ Fac Engn & Ind Technol Div Comp Engn Bangkok Thailand

We propose a shuffling cluster sequence technique without separate side information (SI) for multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) systems. In the proposed technique, the active subcarriers over two consecutive OFDM symbols are divided into 2V$$ 2V $$ clusters, and each cluster (packet frame) includes a header for ID#cluster and payload for Data#cluster$$ Data\# cluster $$. The 2V$$ 2V $$ clusters are shuffled to reduce the peak-to-average power ratio (PAPR) of the time-domain OFDM signal, which includes the information data and SI signals, with a low computational complexity. At the receiver, the information data can be correctly reconstructed by ID#cluster in the header of each cluster, achieving a smaller bit error rate than the conventional MIMO-OFDM system without PAPR reduction. Moreover, our technique is comparable with the conventional partial transmit sequence technique without the impact of a separate SI signal even when increasing the number of transmitter antennas in a nonlinear multipath fading channel.

关键词： computational complexity multiple-input multiple-output system orthogonal frequency-division multiplexing partial transmit sequence peak-to-average power ratio peak-to-average power ratio reduction

来源：评论

学校读者我要写书评

暂无评论

Analysing bit-interleaved coded modulation in multiple-input multiple-output systems with channel estimation error

引用

IET COMMUNICATIONS 2012年第11期6卷 1502-1510页

作者： Andalibi, Z. Nguyen, H. H. Salt, J. E. Univ Saskatchewan Dept Elect & Comp Engn TRlabs Saskatoon SK S7N 5A9 Canada

The performance of bit-interleaved coded modulation in multiple-input multiple-output (BICM-MIMO) systems using an iterative channel estimator is analysed. In a conventional iterative channel estimator, after initialisation with the training phase, the channel estimator switches to the data phase. However, such a conventional iterative channel estimator does not always improve the performance of the receiver. In order to guarantee the performance improvement, a condition on when the output of the decoder should be used by the estimator is determined. Such a condition is related to the reliability of the soft information utilised by the channel estimator. The key in establishing this relationship is to use the mutual information (MI) that the observation vector has about the channel gains given the output of the decoder at each iteration. In this switch-augmented conventional iterative channel estimator, referred to as SAICE, the condition is theoretically found and indicates the needed reliability of the soft information for the channel estimator at the switching time. The switch-augmented scheme guarantees performance improvement of the iterative receiver with each iteration, however, it might need many iterations to converge for moderate to low signal-to-noise ratios (SNRs). A less computationally intensive approach is to use both the training and data segments of the observation. This approach produces a combined iterative channel estimator (CICE) for BICM-MIMO systems. The performance behaviour of the BICM-MIMO system is illustrated through the extrinsic information transfer (EXIT) chart with imperfect channel state information (CSI). Analytical results are verified with computer simulations.

关键词： reliability Communication switching SAICE error Reliability signal-to-noise ratio BICM-MIMO system observation vector multiple-input multiple-output system MI Codes modulation coding imperfect CSI wireless channels iterated switching networks channel estimation combined iterative channel estimator Algebra soft information utilised mutual information channel coding EXIT chart interleaved codes radio receivers bit-interleaved coded modulation analysis less computationally intensive approach radio receiver vectors extrinsic information transfer chart CICE channel estimator switch imperfect channel state information decoder Radio links and equipment Communication channel equalisation and identification iterative decoding SNR switch-augmented conventional iterative channel estimator error telecommunication network reliability MIMO communication

来源：评论

学校读者我要写书评

暂无评论

Error probability performance analysis for multicarrier direct sequence code division multiple access multiple-input-multiple-output systems over correlated η-μ fading channels

引用

IET COMMUNICATIONS 2014年第17期8卷 2971-2983页

作者： Amok, James Osuru Mark Saad, Naufal Mohamed Univ Teknol PETRONAS Dept Elect & Elect Engn Tronoh 31750 Perak Malaysia

The authors investigate the performance of multiple-input-multiple-output multicarrier direct sequence code division multiple access system operating over arbitrarily and equally correlated -mu fading channels in terms of average bit error probability and average symbol error probability. Closed form expressions for average error probability using moment generating function-based approach are derived and expressed in terms of Lauricella's multivariate hypergeometric functions. Furthermore, based on numerical results, they observe that the performance of the system improves when the number of multipath clusters increases as well as the number of subcarriers (frequency diversity). Similarly, substantial enhancement in system performance is observed due to the effect of spatial diversity. Finally, they verify the results via Monte Carlo simulation-based method to support the accuracy of the analytical approach and also compare with already published ones.

关键词： error statistics code division multiple access MIMO communication Monte Carlo methods Nakagami channels spread spectrum communication error probability performance analysis multicarrier direct sequence code division multiple access bit error probability symbol error probability moment generating function based approach Lauricella multivariate hypergeometric function multipath cluster Monte Carlo simulation based method correlated - fading channels multiple-input multiple-output system MIMO systems

来源：评论

学校读者我要写书评

暂无评论

Rate-varying space-time coding scheme for multiple-input multiple-output fading channel with zero-forcing receiver

引用

IET COMMUNICATIONS 2016年第6期10卷 624-631页

作者： Wang, Chao Zhang, Zhaoyang Zhejiang Univ Dept Informat Sci & Elect Engn Hangzhou Peoples R China

In this study, a rate-varying space-time pre-coding scheme for a multiple-input multiple-output system in a fast-fading channel is proposed. In particular, unlike the traditional fixed rate space-time coding scheme, the transmitter which has no channel state information keeps choosing a pre-coding matrix randomly at each space-time symbol period to deliver the information until it is successfully decoded by the receiver. Since the number of received symbol vectors needed to successfully decode the information is determined by the channel realisation, the coding rate of the proposed scheme can adapt to the fast-fading channel. The exact expression of the equivalent signal-to-noise ratio gain after the post-combining and zero-forcing equalisation at the receiver side is derived, and a design criteria to achieve optimal performance in terms of average error probability and ergodic capacity under the mean power constraint is provided. Based on this, a minimal variance pre-coding (MVP) scheme is designed, which is compared with an intuitive Gaussian pre-coding scheme. It is shown that the MVP scheme has better performance and could adapt to different channel conditions.

关键词： MIMO communication space-time codes precoding fading channels error statistics rate-varying space-time precoding scheme multiple-input multiple-output system fast-fading channel channel realisation equivalent signal-to-noise ratio post-combining zero-forcing equalisation design criteria average error probability ergodic capacity mean power constraint minimal variance precoding scheme MVP scheme intuitive Gaussian precoding scheme

来源：评论

学校读者我要写书评

暂无评论

H_∞ control system for a four-high stand rolling mill

引用

PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART I-JOURNAL OF systemS AND CONTROL ENGINEERING 2000年第I2期214卷 79-86页

作者： Lisini, GG Toni, P Valigi, MC Univ Florence Dipartimento Energet I-50139 Florence Italy Univ Perugia Dipartimento Ingn Ind Perugia Italy

In steelworks the demand for a higher product quality level has improved the rolling mill process by means of a proper work roll speed control system. Firstly this paper proposes a lumped-parameter hot-rolling mill model. The rolling mill examined is reversible and equipped with an independent speed control system for each work roll (two single-input single-output systems). Therefore, the same revolution speed, essential for a high-quality process, can only be ensured by equal set point values. Nevertheless, during the process, different disturbance load torques cause speed differences and, even if they are not noticeable, rolled section defects cannot be avoided. The second part of the paper shows that it is possible to design a proper H-infinity controller, to change the two independent control systems into a more complex multiple-input multiple-output system that will obtain decidedly better performances. Simulation examples have shown improvements.

关键词： rolling mill speed control system multiple-input multiple-output system H-infinity control

来源：评论

学校读者我要写书评

暂无评论

Partial automatic repeat request transceiver for bandwidth and power efficient multiple-input-multiple-output orthogonal frequency division multiplexing systems

引用

IET COMMUNICATIONS 2015年第4期9卷 476-486页

作者： Ahmed, Awais Muhammad, Zia Mahmood, Hasan Saqib, Nazar Abbas Quaid I Azam Univ Dept Elect Islamabad 45320 Pakistan Natl Univ Sci & Technol Comp Engn Rawalpindi Punjab Pakistan

In this study, the authors present a novel method to improve the performance of automatic repeat request (ARQ) protocol for multiple-input-multiple-output systems that use orthogonal frequency division multiplexing signalling by incorporating partial ARQ (PARQ) mechanism. As a typical ARQ frame has few number of errors, it is useful to retransmit partial sequence of symbols and recover from errors by consuming relatively low bandwidth. The observations from the first transmission and subsequent retransmission are used for joint detection. As a direct consequence of partial retransmission, the bandwidth and power efficiency of the overall system is improved considerably without substantial decrease in the performance. They achieve further bandwidth saving by omitting pilot sequence from the partial retransmission and acquire channel estimate in semi-blind fashion. Partial retransmission of the original information symbol sequence allows the authors to formulate second-order statistics based joint blind channel estimation problem by combining observations from two transmissions. Channel estimation ambiguity inherent to blind methods is resolved by combining cost functions of blind detection and least-square estimator. To evaluate efficacy of the proposed PARQ method, they compare throughput of chase-type hybrid-ARQ and the proposed PARQ methods.

关键词： automatic repeat request radio transceivers MIMO communication OFDM modulation telecommunication power management channel estimation higher order statistics least squares approximations wireless channels signalling protocols MIMO-OFDM systems multiple-input multiple-output system chase-type hybrid-ARQ least-square estimator joint blind channel estimation problem second-order statistics information symbol sequence partial retransmission semiblind fashion channel estimation bandwidth saving power efficiency improvement bandwidth efficiency improvement joint detection orthogonal frequency division multiplexing signalling PARQ mechanism ARQ protocol partial automatic repeat request transceiver

来源：评论

学校读者我要写书评

暂无评论

Semi-definite relaxation decoder for 256-QAM MIMO system

引用

ELECTRONICS LETTERS 2010年第11期46卷 796-U95页

作者： Shao, Z. Y. Cheung, S. W. Yuk, T. I. Univ Hong Kong Dept Elect & Elect Engn Hong Kong Hong Kong Peoples R China

A semi-definite relaxation decoder is proposed for a multiple-input multiple-output (MIMO) system based on 256-QAM constellation. Simulation results indicate that it is computationally efficient and can provide better... 详细信息

关键词： 256-QAM MIMO system MIMO communication block-error-rate performance decoding multiple-input multiple-output system quadrature amplitude modulation semi-definite relaxation decoder sub-optimal decoder

来源：评论

学校读者我要写书评

暂无评论

Beamforming and combining for multi-user large MIMO communication system

引用

IET COMMUNICATIONS 2020年第19期14卷 3334-3339页

作者： Arti, M. K. Rani, Pratibha Dimri, Pradeep Kumar Vashishath, Munish Ambedkar Inst Adv Commun Technol & Res New Delhi 110031 India JC Bose Univ Sci & Technol YMCA Sec 6 Faridabad 121006 Haryana India

A beamforming and combining method for a multi-user large multiple-input multiple-output (MIMO) system is proposed, in this study. A transmitter is equipped with a very large number of antennas to serve many users. At the transmitter, a group of antennas is allocated to each user. For a particular group of antennas, a specific beamforming vector is employed at the transmitter for transmission of a signal of a specific user. At the user end, a distinct combining vector is utilised for detecting the transmitted signal. In the proposed scheme, first, the interference due to unwanted signals of undesired users is nullified by using the concept of null space. Then the method of maximum ratio transmission is used to calculate the beamforming vector. The calculation of combining vector depends upon the maximum eigenvalue criterion. The analytical performance of the proposed method is discussed in terms of symbol error rate (SER). An expression of SER is derived by using the moment generating function approach. It is shown by simulations and analysis that the proposed scheme performs better if more antennas are equipped either at the transmitter or users.

关键词： MIMO communication error statistics array signal processing eigenvalues and eigenfunctions transmitting antennas diversity reception maximum eigenvalue criterion transmitter MIMO communication system combining method multiple-input multiple-output system beamforming vector distinct combining vector transmitted signal unwanted signals maximum ratio transmission multiuser large MIMO system symbol error rate moment generating function

来源：评论

学校读者我要写书评

暂无评论

Effect of composite channel aging on the spectral efficiency of multi-pair massive multiple-input multiple-output amplify-and-forward relay networks

引用

IET COMMUNICATIONS 2017年第8期11卷 1313-1324页

作者： Chen, Yuanyuan Liu, Chen Wang, Hairong Zhu, Wei-Ping Nanjing Univ Posts & Telecommun Sch Elect Sci & Engn Nanjing Jiangsu Peoples R China Nanjing Univ Posts & Telecommun Sch Commun & Informat Engn Nanjing Jiangsu Peoples R China Concordia Univ Dept Elect & Comp Engn Montreal PQ Canada

This study investigates the spectral efficiency of multi-pair massive multiple-input multiple-output amplify-and-forward relay networks by considering the composite channel aging effect. The rational of this work is that the channel aging effect caused by phase noise and node movements is an inevitable practical channel impairment in time-varying fading channels and substantially degrades the performance. The proposed model comprises multiple sources and multiple destinations, each equipped with a single antenna, which communication via a relay equipped with a very large number of antennas by employing maximal-ratio combining/maximum-ratio transmission. Based on this model, the authors first derive a closed-form lower bound expression for the achievable rate of per source-destination pair. Then, by using the derived expression, they study how the transmitted powers of each source and the relay can be reduced without compromising the spectral efficiency when the number of relay antennas approaches infinity. They also discuss the effect of channel aging coefficients, including Doppler shift and phase noise increment variance, on the asymptotic spectral efficiency under different power scaling laws. Both theoretical analysis and Monte Carlo simulations disclose that the channel aging effect does not affect the power scaling laws but degrades the spectral efficiency.

关键词： MIMO communication amplify and forward communication relay networks (telecommunication) diversity reception fading channels antenna arrays Monte Carlo methods Doppler shift phase noise composite channel aging effect multipair massive MIMO amplify-and- forward relay network node movements inevitable practical channel impairment time-varying fading channel single antenna maximal-ratio transmission maximal-ratio combining closed-form lower bound expression source-destination pair relay antennas Doppler shift phase noise increment variance asymptotic spectral efficiency power scaling laws Monte Carlo simulation multiple-input multiple-output system

来源：评论

学校读者我要写书评

暂无评论

Optimal power allocation in a MIMO-OFDM twisted pair transmission system with far-end crosstalk

Optimal power allocation in a MIMO-OFDM twisted pair transmi...

引用

International Conference on Signal Processing and Multimedia Applications

作者： Ahrens, Andreas Lange, Christoph Univ Rostock Inst Commun Engn Richard Wagner Str 31 D-18119 Rostock Germany

ISBN: (纸本)9728865643

Crosstalk between neighbouring wire pairs is one of the major impairments in digital transmission via multipair copper cables, which essentially limits the transmission quality and the throughput of such cables. For high-rate transmission, often the strong near-end crosstalk (NEXT) disturbance is avoided or suppressed and only the far-end crosstalk (FEXT) remains as crosstalk influence. If FEXT is present, signal parts are transmitted via the FEXT paths from the transmitter to the receiver in addition to the direct transmission paths. Therefore transmission schemes are of great practical interest, which take advantage of the signal parts transmitted via the FEXT paths. Here a SVD (singular-value decomposition) equalized MIMO-OFDM system is investigated, which is able to take advantage of the FEXT signal path. Based on the Lagrange multiplier method an optimal power allocation schema is considered in order to reduce the overall bit-error rate at a fixed data rate and fixed QAM constellation sizes. Thereby an interesting combination of SVD equalization and power allocation is considered, where the transmit power is not only adapted to the subchannels but rather to the symbol amplitudes of the SVD equalized data block. As a result it can be seen that the exploitation of FEXT is important for wireline transmission systems in particular with high couplings between neighbouring wire pairs and the power allocation is possible taking the different subcarriers into account.

关键词： twisted-pair cable OFDM power allocation multiple-input multiple-output system Lagrange multiplier method singular-value decomposition

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：